JP2636567B2 - Magnetic recording medium and magnetic disk drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device, which is an external storage device of a computer, and a magnetic recording medium used in the device.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional flexible disk shown on page 224 of "Latest Floppy Disk Drive and Its Application Know-how", written by Shoji Takahashi, published by CQ Publishing Company. In the figure, 1 is a disk, 2 is a center hole provided in the center of the disk 1, 3 is an index hole provided on the disk 1, 4 is a circle concentric with the center hole 2 and a These are sector holes provided on the same circle. Numeral 5 is a track recorded on the disk 1 and numeral 6 is a sector divided on the track 5 by a gap 7.

FIG. 5 shows a disk cartridge 8 in which the disk 1 shown in FIG. 4 is stored in a jacket, 9 is a central window for connecting a center hole 2 to a spindle motor hub of a magnetic disk drive, and 10 is a sector hole 3. And an index window which is an opening for detecting the index hole 4. Reference numeral 11 denotes a head window for the magnetic head to come into contact with the medium.

FIG. 6 is a view showing a state where the disk cartridge 8 shown in FIG. 5 is mounted in a magnetic disk device. Reference numerals 12 and 13 denote a light emitting element and a light receiving element which are arranged correspondingly with the index window 9 of the disk cartridge 8 interposed therebetween, and detect an index and a sector by passing and blocking light by the index hole 3 and the sector hole 4. Things. Reference numeral 14 denotes a magnetic head for performing writing and reading on the disk 1.

Next, the operation will be described. When the disk cartridge 8 is mounted in the magnetic disk device,
The center point is positioned by fitting the central hole 2 of the disk 1 with the spindle motor hub of the magnetic disk device. In this state, the disk 1 is driven by the spindle motor.
When the is rotated, the index hole 3 and the sector hole 4 pass through the index window 10 and the light emitting element,
Passes and blocks light between light receiving elements. Based on the interval between the passage and blocking of the light, it is recognized whether the light is caused by the index hole 3 or the sector hole 4, and the index and the starting point of the sector are determined.

[0006]

SUMMARY OF THE INVENTION Conventional indexes,
Since the sector detection is configured as described above, the window is always opened in the jacket and dust enters, causing a data error. In addition, since only the passage and blocking of light by index holes and sector holes are used as the basis of the sector, variations and aging of the light emitting element and the light receiving element or the assembly accuracy between the magnetic head and the light emitting element and the light receiving element may cause the sector hole. If there is a gap between the detected sector and the sector magnetically written on the medium, there is a problem that the storage area is wasted.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and a magnetic disk drive capable of preventing dust from entering a medium and minimizing storage area waste. The purpose is to gain.

[0008]

According to the present invention, there is provided a magnetic recording medium comprising: a plurality of sector holes provided at positions corresponding to the sectors on the track on the outer circumference concentric with the tracks on the disk; A sector window provided in the cassette so as to be able to see through a sector hole of the disk, wherein the sector window of the cassette is provided with a shutter provided when a shutter provided in the cassette is at a position for closing the head window. The shutter is provided at a position where it is exposed when the shutter is at a position where the head window is opened.

In a magnetic recording medium according to another aspect of the present invention, a switch for changing the function of the medium is provided on the cassette, and the switch for changing the function of the medium is covered by the shutter when the shutter is in the position for closing the head window. The shutter is provided at a position where the shutter is exposed when the head window is opened.

According to another aspect of the present invention, a light emitting element and a light receiving element are provided so as to correspond to the sector holes of the cassette. A magnetic disk device that writes a specific magnetic pattern on a disk by using a magnetic disk device. A timer for measuring a time until a specific magnetic pattern is detected is provided.

[0011]

According to the present invention, since the opening provided in the cassette is exposed only when used, dust is less likely to enter when not in use. Furthermore, since a specific magnetic pattern can be written and used as a time reference, highly accurate timing extraction can be performed, and waste of the storage area can be reduced.

[0012]

【Example】

Embodiment 1 FIG. FIG. 1 shows a magnetic recording medium according to an embodiment of the present invention, and reference numerals 1 to 13 are the same as those of the conventional apparatus shown in FIGS. 1 is a disk, 4 is a sector hole,
5 is a track, 6 is a sector, and 7 is a gap. . The sector holes 4 are provided on the outer periphery of the disk 1 at equal intervals on a concentric circle, and the tracks 5 are magnetically recorded on the disk.
Is divided into

FIG. 2 is a view showing a cassette accommodating the disk shown in FIG. 1. Reference numeral 15 denotes a shutter capable of opening and closing a head window, and reference numeral 16 denotes a sector window provided at a position where a sector hole can be seen through. It is. In addition,
The sector window 16 is open when the drive is mounted (FIG. 2A), and is hidden by the shutter 15 when the drive is not mounted (FIG. 2B).

FIG. 3 is a view when the cassette shown in FIG. 2 is mounted on a magnetic disk drive. The shutter of the cassette is released by a shutter opener (not shown), and a sector hole is exposed. The light emitting element 12 and the light receiving element 13 face each other across the sector window 16 of the cassette 8 to form a sector detector. The magnetic head 14 contacts the disk through the head window 11.

The operation will be described below. In FIG. 3, when the cassette is set in the disk device, the disk 1 is also chucked by the spindle motor (not shown) of the disk device. At this time, the disk is accurately centered by rotation of a spindle motor (not shown). Thereby, the light emitting element 12 and the light receiving element 13
Both accurately detect the sector hole 4 opened on the disk 1 through the sector window 16 of the cassette.

When the magnetic head 14 is positioned on the predetermined track 5, a sector is detected when the sector hole 4 passes between the light emitting element 12 and the light receiving element 13. At this time, the magnetic head 14 is located in the sector gap 7 on the track 5. The disk device can know the start timing of the sector by detecting the sector, and starts writing and reading data. (FIG. 7)

Embodiment 2 FIG. FIG. 8 is a diagram showing a magnetic recording medium and a magnetic disk drive capable of more accurate sector detection. As shown in FIG. 8, when the disk 1 is separated from a normal data area when the disk 1 is initialized, for example,-
A sector mark 17 is magnetically written on one track so as to coincide with the beginning of a sector on each track. In this state,
By measuring the time between the detection of the sector hole 4 and the detection of the sector mark 17 by using a timer, for example, when there is a variation in the light emitting element 12 and the light receiving element 13 and a variation in the mounting positions of the two elements and the magnetic head. However, it is possible to detect how much the sector hole 4 deviates from the start timing of the sector recorded on the disk 1. By storing this deviation amount as the correction timing, even when the magnetic head moves to the normal data area, the detection timing of the sector hole 4 and the sector start timing on the disk 1 can be accurately known from the correction timing. it can.

Embodiment 3 FIG. FIG. 9 shows a case where a servo area 18 for positioning a magnetic head is provided at the head of a sector. For example, in an even-numbered track, a signal of an appropriate frequency is written in a servo area A and a servo area B is written. Is deleted. Conversely, in an odd track, the servo area A is erased and a signal of an appropriate frequency is written in the servo area B. When the magnetic head 14 passes through the center of the track (trajectory X) in this state, the output of the magnetic head 14 becomes as shown in FIG. 9, and the amplitude of the magnetic head output signal in the servo area A and the servo area B is reduced. Become equal. If the magnetic head 14 is displaced from the center of the track, there will be a difference between the amplitudes of the magnetic head output signals in the servo area A and the servo area B. The position of the magnetic head 14 is adjusted based on this difference. The timing at which the positioning circuit (not shown) takes in the output signal amplitude of the magnetic head in the servo area 18 can be obtained by the sector hole 16. The timer is operated from the time when the sector hole passes, and the magnetic head output signal amplitude of the servo area A is captured when the time Ta has elapsed, and the magnetic head output signal amplitude of the servo area B is captured when the time Tb has elapsed. The required data is obtained.

Embodiment 4 FIG. In the above embodiment, the servo area 18 for positioning has been described as being written on the disk 1 in advance. However, the magnetic disk device according to the present invention can perform self-servo writing by utilizing the detection of a sector hole. This will be described with reference to FIG.
In FIG. 10, the magnetic head 14 is roughly positioned on an arbitrary track. At this time, for example, when the track is an even track, the timer is operated from the time when the sector hole is detected, and writing is performed at a predetermined frequency from time T1 to time T2. By this operation, the servo area A is written. DC erasing is performed from time T2 to time T3. By this operation, the servo area B is written. If the positioned track is an odd-numbered track, on the contrary, DC erasure is performed from time T1 to time T2. From time T2 to T3, writing is performed at a predetermined frequency. By repeating this, writing to the servo area 18 is performed.

Embodiment 5 FIG. In the above embodiment, the magnetic head 14
Has been described in the case where the core width is almost the same as the track 5 width. However, writing can be similarly performed even when the core width of the magnetic head 14 is wider than the track width. This will be described with reference to FIG. In FIG. 11, the magnetic head 14 is roughly positioned on an arbitrary track. At this time, for example, when the track is an even track, the timer is operated from the time when the sector hole is detected, and the time T1 is set to the time T1.
Writing is performed at a predetermined frequency up to 2. By this operation, the servo area A is written. DC erasing is performed from time T2 to time T3. By this operation, the servo area B is written. At this time, the width of the written servo area becomes wider than the original track width, similarly to the core width of the magnetic head 14. Next, the magnetic head 14 is shifted by the original track width. At this time, the magnetic head 14 is positioned on an odd track. In this state, DC is erased from time T1 to T2. From time T2 to T3, writing is performed at a predetermined frequency. Only the displacement of the magnetic head 14 by this operation becomes the servo area 18 and remains on the disk. By repeating this, writing to the servo area 18 is performed.

Embodiment 6 FIG. FIG. 12 shows an embodiment in which a servo area 18 is provided at the head of the sector shown in FIG. 9, and more accurate sector detection is realized. In the figure, a sector mark 17 is magnetically written on an area of the disk 1 not used as a data area. This is because the servo area 18 for positioning the magnetic head as described in FIG. 9 does not exist, and the positioning of the magnetic head becomes inaccurate. Therefore, it is preferable to use a magnetic head having a wide track width. Disk 1 on which this servo mark 17 is written
Is used, first, the magnetic head 14 is set to the servo mark 17.
Moves to the area where is written. Next, the timing for detecting the sector hole 4 and the timing for detecting the servo mark 17 read from the magnetic head 14 are measured using a timer. Suppose that this is usually measured as Tm + Tx where it should be Tm, for example.
The difference, that is, Tx corresponds to the variation between the light emitting element 12 and the light receiving element 13 or the variation generated when the light emitting element 12, the light receiving element 13 and the magnetic head 14 are attached. Tx is stored in order to absorb this variation, and when the magnetic head is positioned in the data area, the amplitude of the magnetic head output signal in the servo area A is normally taken at Ta after the detection of the sector hole 4. Ta + Tx
Fetches the magnetic head output signal amplitude in the servo area A.
Similarly, when the magnetic head output signal amplitude of the servo area B is captured at Tb after the detection of the sector hole, the magnetic head output signal amplitude of the servo area A is captured at Tb + Tx. This makes it possible to absorb variations due to various factors.

Embodiment 7 FIG. FIG. 13 shows a case where the above-described magnetic recording medium is mounted on a magnetic disk device, and a case where a function changeover switch 19 is provided on the cassette 8 in order to identify the cassette from the conventional magnetic recording medium. By detecting the function changeover switch 19 of the medium, it is possible to recognize that the medium has the sector hole 4 and that writing is prohibited. When the cassette is not used, the function changeover switch 19 for the medium is also closed by the shutter, so that there is no danger of dust entering from outside.

Embodiment 8 FIG. Although the sector hole is illustrated as a round hole in the above embodiment, the sector hole may have a fan shape as shown in FIG. 14, a square shape, or a notch as shown in FIG. Good.

Embodiment 9 FIG. In the above embodiment, the sector hole 4 is described as a hole. However, the disk surface may be replaced with a seal or a paint having a different light reflectance from the disk surface, and the disk surface may have irregularities. Alternatively, a sector hole 4 may be provided. In these cases, it is necessary to use a reflection type sensor through the sector window 16 as shown in FIG.

Embodiment 10 FIG. In the above embodiment, the data sector 6 and the sector hole 4 have been described as one-to-one.
A plurality of data sectors may be included between two sector holes, and as shown in FIG. 17, one or a plurality of index holes 3 are provided on the same circumference as the sector hole 4 in one round, and May be detected and used as the starting point of rotation.

[0026]

As described above, according to the present invention, since the opening provided in the cassette is exposed only when used, dust is less likely to enter when not in use. Furthermore, since a specific magnetic pattern can be written and used as a time reference, highly accurate timing extraction can be performed.
There is an effect that waste of the storage area can be omitted.

[Brief description of the drawings]

FIG. 1 is a diagram showing a disk according to an embodiment of the present invention.

FIG. 2 is a diagram showing a cassette according to an embodiment of the present invention.

FIG. 3 is a diagram when a cassette is mounted on the magnetic disk drive according to one embodiment of the present invention;

FIG. 4 is a diagram showing a conventional disk.

FIG. 5 is a view showing a conventional disk cartridge.

FIG. 6 is a diagram when a conventional disk cartridge is mounted on a conventional magnetic disk device.

FIG. 7 is a diagram illustrating the relationship between the detection timing of a sector hole and the head of a data sector.

FIG. 8 is a diagram illustrating the detection timing of a sector hole when a sector mark is written on a disk, and the relationship between the sector mark and the beginning of a data sector.

FIG. 9 is a diagram illustrating the relationship between the detection timing of a sector hole and the servo area when a servo area is written at the head of a data sector.

FIG. 10 is a diagram illustrating a method of writing a servo area at the beginning of a data sector.

FIG. 11 is a diagram illustrating a method of writing a servo area at the beginning of a data sector using a magnetic head having a wide core width.

FIG. 12 is a diagram for explaining a relationship between a sector hole detection timing, a sector mark, and a servo area when a sector mark is written on a disk and a servo area is written at the head of a data sector.

FIG. 13 is a view showing a cassette according to an embodiment of the present invention.

FIG. 14 is a diagram showing a disk according to another embodiment of the present invention.

FIG. 15 is a diagram showing a disk according to another embodiment of the present invention.

FIG. 16 is a diagram showing a method for detecting a sector hole according to another embodiment of the present invention.

FIG. 17 is a diagram showing a disk in which index holes are provided on the same circle as a sector hole.

[Explanation of symbols]

 Reference Signs List 1 disk 2 center hole 3 index hole 4 sector hole 5 track 6 data sector 7 sector gap 8 disk cartridge or cassette 9 center window 10 index window 11 head window 12 light emitting element 13 light receiving element 14 magnetic head 15 shutter 16 sector window 17 sector mark 18 Servo area

Claims (9)

(57) [Claims] 1. A magnetic recording medium comprising: a cassette having a shutter for opening and closing a head window; and a disk-shaped magnetic disk accommodated in the cassette and having concentric tracks drawn thereon. A plurality of sector holes provided on a circumference; and a sector window provided in the cassette so as to be able to see through the sector holes of the disk. A magnetic recording medium, wherein the magnetic recording medium is covered by the shutter when the shutter is in a closed position, and is provided in an exposed position when the shutter is in a position to open the head window. 2. A cassette having a medium function changeover switch provided on the cassette, wherein the medium function changeover switch does not overlap with the disk and is covered by the shutter when the shutter is at a position for closing the head window. 2. The magnetic recording medium according to claim 1, wherein a shutter is provided at a position where the shutter is exposed when the head window is opened. 3. A magnetic disk drive using the magnetic recording medium according to claim 1 and having moving means for moving a shutter to a position where a head window opens when the magnetic recording medium is mounted. A magnetic disk drive provided with a sensor provided corresponding to a sector window provided in a cassette and detecting a sector hole of a disk through the sector window. 4. A magnetic disk drive using the magnetic recording medium according to claim 2 and having moving means for moving a shutter to a position where a head window opens when the magnetic recording medium is mounted. A magnetic disk drive, wherein a sensor is provided corresponding to the medium function changeover switch provided in the magnetic disk drive, and the medium function changeover switch is detected. 5. A magnetic disk drive according to claim 3, wherein a signal for writing a sector mark on a medium is generated by using a magnetic head after a predetermined time has elapsed after detecting a sector hole of the disk by a sensor. A magnetic disk drive provided with a timer. 6. A magnetic disk drive according to claim 3, wherein a signal for writing a servo pattern on a medium is generated by using a magnetic head after a predetermined time has elapsed after detecting a sector hole of the disk by a sensor. A magnetic disk drive provided with a timer. 7. The magnetic disk drive according to claim 3, further comprising: a timer for measuring a timing of detecting a sector hole of the disk by a sensor and an interval of detecting the magnetic pattern on the medium. A magnetic disk drive, wherein the detection timing of the sector is corrected. 8. A magnetic disk drive according to claim 3, wherein a predetermined time has passed after a plurality of magnetic heads having different core widths are incorporated in one head slider and a sector hole of the disk is detected by a sensor. And a timer for generating a signal for writing a sector mark on a medium using a magnetic head having a larger core width. 9. A magnetic disk drive according to claim 3, wherein a predetermined time has elapsed after detecting a sector hole of the disk by a head in which a plurality of magnetic heads having different core widths are incorporated in one head slider and a sensor. And a timer for generating a servo pattern write signal on the medium using a magnetic head having a larger core width.